The thermoelectric effect involves the direct conversion of temperature differences to electric voltage and vice versa. A thermoelectric device creates a voltage when there is a sufficient temperature differential across the device. Conversely, when a sufficiently-strong voltage is applied to the thermoelectric device, it creates a temperature difference.
Thermoelectric devices may be used to measure temperature, to generate electricity, to cool objects, or to heat objects. Thermoelectric devices are solid-state devices and generally have no moving parts. Thermoelectric generators (also called thermogenerators) are thermoelectric devices which convert heat—in the form of temperature differences—directly into electrical energy, using the Seebeck effect.